Method of producing ethyl substituted cyclic compounds



United States Patent 3 333 013 METHOD OF PRGDUIN} ETHY L SUBSTITUTEDCYCLIC COMPOUNDS from parafiinic hydrocarbons and cyclic compoundshaving at least one methyl substituent. It is also an object of thepresent invention to provide a new and novel thermal, non-catalyticprocess for producing ethyl-substituted cyclic gf gii gfij g gggggfifigg f ig g gbggfg? 5 compounds. Still another object of the presentinvention is Louis, Mo a corporation of Delaware to provide a new andnovel process for producing ethyl- N D i Filed Jam 22, 19 5 Sen 427,501benzene. Additional ob ects will become apparent from 19 Claims. (Cl.260-468) the following description of the invention herein disclosed.

In fulfillment of these and other objects, it has been The presentinvention relates to a process for producing found thatethyl-substituted cyclic compounds may be obethyl-substituted cycliccompounds. More particularly, the tained in good yields by means of aprocess which compresent invention relates to a process for producingethylprises introducing paraifin hydrocarbons and an unsatusubstitutedcyclic compounds from paraffinic hydrocarbons rated cyclic compoundhaving at least one methyl-suband unsaturated cyclic compounds having atleast one stituent into a reaction zone concurrently with amodifyingmethyl substituent on the cyclic ring. 5 agent selected from the groupconsisting of compounds Vinyl cyclic, compounds, particularly styrene,are well and elements which at the conditions of the reaction zone knownmonomers which on polymerization produce verill p od e a compound S leted from the group 0011- satile plastics having a multitude ofapplications. Most Sisting of 2 and Combinations e often, thesemonomers, which are in great demand, are obthe reaction zone beingmaintained at a temperature of at tained by the dehydrogenation of thecorresponding ethyl- 20 least ahd a Pressure of at least 100 P-substituted cyclic compound. For instance, styrene, the To furtherdescribe and to illustrate the present invenmost widely known and usedof the vinyl-substituted cyclic n, th following examples are presented.These x mp monomers, is usually obtained by the dehydrogenation of arein no manner to be construed as limiting the present ethylbenzene. Thisethylbenzene is, in turn, usually obnv ti tained by the fractionation ofrelatively complex mixtures XAMPLE I of petroleum-derived compoundswhich generally include Q in addition to ethylbenzene, o-, m-, andp-xylenes, T Five separate runs were carried out with a feedconsistseparate ethylbenzene from the xylenes, particularly mihg 0ftehlehe and a -P The runs were carried out and p-Xylene, byfractionation is a rather diificult and y Placing a q y of each of thereactants i a expensive operation and, unless the quantity ofethylbencapacity bomb- In four of the runs, an amount of O 9 zene in themixture is rather significant, is usually not the modifying agents ofthe Present invention Sufficient to economically attra tiv produce aconcentration of 1 mole percent of the total In addition to recoveringethyl-substituted cyclic commixture was added to the bomb- After thereactants pounds by fractionation, synthetic methods for producingreactants and modifying agent Were Placed in the bomb, it such compoundshave received considerable attention. was Sealed and heated to atemperature of and Among the mor prominent means b hi h h p maintainedat that temperature for about 20 minutes. The

stituted cyclic compounds are synthetically produced, is Pressure Wasalltegehells- The table below gives the the alkylation of a cyclicnucleus with a paraflin or an oleamount of toluene, the identity andamount of the fin followed, generally, by dealkylation to remove excess-p the pertielllal' modifying agent used, if y, methyl groups. Ofcourse, by alkylation with ethane or 40 and the Percent Conversion toethylbenzene Toluene n-Parafiin Percent R Modifying Agent Conversion toEthylbenzene Gram Mole Type Gram Mole 1 0.784 .00853 05 0.266 0.003692-bromopropane... 17.8 2 0. 780 .00848 Ci 0.260 0. 00301 do 12.8 a 0.78100849 or 0. 224 0. 00311 o. 14.8 4 0. 705 00832 or 0.220 0.00300Benzenethiol. 0.7 a i- 0.757 00823 Cs 0.218 0.00303 None 1,5

ethylene, an ethyl-substituted cyclic compound may be ob- Comparison ofthe results obtained in the above detained. However, ethylene so readilypolymerizes under scribed runs dramatically illustrate the substantiallyinconditions ordinarily necessary to alkylation that it is not creasedconversions resulting from the present invention.

practical for use as an alkylating material. To alkylate R1111 thepoorest of the runs made in the Presence a with ethane usually wouldrequire obtaining a relatively modifying agent in accordance with thepresent invention pure ethane fraction, followed b halogenafion f hresulted in an approximate 546% increase in conversion ethane to obtainan ethyl halide which may then be alkyl- Over Run 5 which was made undersubstantially the Bethe ated onto the cyclic nucleus. Also, in mostinstances such eohditlehs, but not In the Pf e Of One Of the yalkylationand the subsequent dealkylation require catamg agents of the i mventlon-Run 1, t best o lysts which increase the cost of synthetically producingthe runs madam the Presenc? of a mqdlfymg e t ethyl subsfituted cycliccompounds. resulted in an approximate 1088% increase in conversion It isan object of the present invention to provide a Over Run process forproducing ethyl-substituted cyclic compounds. EXAMPLE II Another objectof the present invention is to provide a process for producingethyl-substituted cyclic compounds A run was carried out under the sameconditions of temperature, time and pressure and with the reaction bombof Example I. In this run the feed consisted of 0.64 gram (0.00603 mole)of p-xylene and 0.195 gram (0.00271 mole) n-pentane. Z-bromopropane wasused as the modifying agent in a concentration of one mole percent ofthe feed-modifying agent mixture. A conversion to p-ethyltoluene of 12.8percent was obtained.

EXAMPLE III A run is carried out by placing approximately equal moles ofmethylpyridine and n-butane in a reaction bomb of approximately oneliter capacity. Bromobenzene is added to the reaction bomb in an amountsuch that its concentration in the bomb is approximately 3 mole percentof the mixture. The bomb is then heated to a temperature of 525 C. andbrought to a pressure of 5000 p.s.i.g. under which conditions it ismaintained for about 15 minutes. A good conversion of methylpyridine toethylpyridine is obtained.

EXAMPLE IV The run of Example III is substantially repeated with theexception that the feed consists of an approximately equal molarconcentration of l-methylnaphthalene and n-pentane. 3-chlorohexane isused as the modifying agent in this run in a concentration ofapproximately 0.5 mole percent of the total mixture. A good conversionof the l-methylnaphthalene to ethylnaphthalene is obtained.

EXAMPLE V The run of Example III is again substantially repeated withthe exception that the feed consists of l-rnethylcyclopentene andn-propane in a molar ratio of 1 to 2, n-propane to methylcyclopenteneand the modifying agent is hexyl mercaptan present in a concentration of2.5 mole percent of the total mixture. A good conversion of themethylcyclopentene to ethylcyclopentene is obtained.

EXAMPLE VI Run 1 of Example I is substantially repeated with theexception that the paraflin hydrocarbon is n-nonane. A good conversionto ethylbenzene is obtained.

EXAMPLE VII Run 1 of Example I is substantially repeated with theexception that Z-methylpentane is the parafiin hydrocarbon. A goodconversion to ethylbenzene is obtained.

The unsaturated cyclic compounds useful as reactants in the process ofthe present invention must contain at least one methyl-substituent onthe cyclic nucleus. These methyl-substituted unsaturated cycliccompounds are lmethyl-substituted unsaturated cyclics in which themethyl-substituent is attached to a carbon atom of the cyclic nucleuswhich carbon atom is adjacent to double bond unsaturation of the-cyclicnucleus. Such methyl-substituted cyclic compounds includemethyl-substituted aromatic hydrocarbons, both mono-nuclear andpoly-nuclear, heterocyclic compounds, and cyclo-olefinic and di-olefinichydrocarbons. In addition to the required methyl-substituent on thecyclic nucleus, the cyclic compound may contain othermethyl-substituents or other alkyl-substituents such as ethyl, propyl,and the like. Among the methyl-substituted aromatic hydrocarbons aresuch compounds as ethyltoluene, toluene, mand p-xylene, 1,3-diethyl-S-methylbenzene, 1-methylnaphthalene, Z-methylnaphthalene,di-methylnaphthalenes, 1,3,5-tri-methylbenzene, l-methylphenanthrene,and the like. The methylsubstituted aromatic hydrocarbons also includethe partially and totally condensed poly-nuclear aromatics among whichare such compounds as methyl octa-hydronaphthalene, methyl-substitutedtetralins, methyl-substituted dihydronaphthalenes, and the like. Themethyl-substituted heterocyclic compounds include such compounds asmethylpyridine, dimethylpyridines, trimethylpyridines, methyl- 4ethylpyridines, methyldihydropyran, methylpyran, dimethyldihydropyrans,dimethylpyrans, methylethylpyrans,

methylfuran, dimethylfurans, methylsulfolene, dimethylsulfolenes,methylethylsulfolenes, methylsulfolene, dimethyl sulfolenes,methylbenzofuran, methylthionaphthalene, methylindole and the like.Included within the methyl-substituted cycloolefin and di-olefinshydrocarbons are such compounds as l-methyl cyclopentene, 1-methylcyclohexene, l-methyl cycloheptene, l-methyl cyclooctene, 1,2-dim-ethylcyclopentenes, 1,3-dimethylcyclohexenes, dimethyl cycloheptenes,l-inethyl-ethyl cyclopentenes, methyl ethyl cyclohexenes, l-methylcyclopentadiene, 1-methyl cycloheptadienes and the like. Thel-methyl-substituted unsaturated cyclic compounds most often used asfeeds in the practice of the present invention are those which have nosubstituents other than methyl-substituents and which have no more thanthree methyl-substituents. Preferred among the l-methyl-substitutedcyclic unsaturated compounds are the methyl-substituted aromatichydrocarbons, particularly toluene, the xylenes, methyl naphthalenes anddimethyl naphthalenes. Since the most useful of the resulting productsat present is ethylbenzene, then the most useful of themethyl-substituted cyclic compounds is toluene.

The methyl-substituted cyclic compounds may have in addition to themethyl substituent such non-hydrocarbon substituents as alkoxy groups,nitro graups and the like.

The parafiin hydrocarbons useful in the practice of the presentinvention may be either branched-chain or straight-chain. Most often,the paraifin hydrocarbon contains no less than 2 or more than 20 carbonatoms per molecule. If branched-chain, the parafiin hydrocarbon may haveone or several branches with the same or varying numbers of carbon atomsin the branches. Usually,

Z-methyl-S-ethylhcptane, 3,3-diethylhexane, 3-methyloctane,3-methylnonane, 4,5-dimethyloctane, and the like. Particularly usefulparaflin hydrocarbons are the n-paraffins of 3 to 10 carbon atoms permolecule with those of 4 to 8 carbon atoms preferred.

The amount of the reactants of the process of the present invention mayvary over wide ranges. However, most often the mole ratio of paraffinhydrocarbon to methylsubstituted unsaturated cyclic compound is withinthe range of 1:100 to :1. In the particularly useful manner ofpracticing the present invention, the mole ratio of paraffinhydrocarbons to methyl-substituted unsaturated cyclic compounds iswithin the range of 1:5 to 5:1.

The modifying agents useful in the present invention comprise materialswhich under the conditions of the thermal reaction zone will decomposeor otherwise form hydrogen chloride, hydrogen bromide, hydrogen iodide,hydrogen sulfide or combinations thereof. The term agent is meant toinclude, in the sense used herein, elemental sulfur, chlorine, bromine,and iodine as well as well as chemical compounds of which these elementsare a part. The compounds which contain chlorine, bromine, iodine orsulfur may be either organic or inorganic compounds and may contain inaddition to these elements such other elements as carbon, hydrogen,oxygen, or nitrogen. If the compound is an organic compound, it may besaturated or unsaturated, aliphatic or aromatic, straight-chain,branched-chain or cyclic in structure. Among the halogen-containingcompounds within the scope of the present invention are the followingnon limiting examples:

Column I Column II Column III 2-brornopropane 2-chloropropane.l-iodopropanel l-brornopentane. 2-brornopentane 3-chloropentane2-iodopentane 3-bromohexane 2-bromohexane A 2-iodohexane2-bromo-4-methylhexane. 3-chloroheptene 3-bromoheptane 2-iodoheptane2-bromo-4-ethylhexane. 4-bromooctane.-

3-chlorooetane 2-iodooctane l-bromononaneflfi 2-ehlo;odocane2-bromodecane 2-brorno-6-rnethyldecane. 4-iodoundecaue lbrornododecanefl Hydrogen chloride. Hydrogen bromide.. Hydrogen iodideBrornobenzene Chlorobenzene rn-Dichlorobenzene o-Dichlorobenzene.p-Dichlorobenzenem-Dibromobenzene. o-Dibromobcnzene p-Dibromobenzeneo-Ohlorotoluene m-Chlorotoluene p-chlorotoluene o-B rornotoluene.

m-Bromotoluene. p-Brornotolu'ene 1, 3-dichloronaphthalene.2chlorodiphenyl 4-chlorodiphenyl Chlorine gas Bromine gas IodineOhloroethanoic acid. Dibromoethanoic acid. Di-iodoethanoic acid.a-Chloroacetamide. a-bromoacetauilide. Benzoyl chloride. Denzoylbromide.

'Benzoyl iodide.

Butanoyl chloride.

.. Butanoyl bromide.

Butanoyliodide. 2-ch1oro-l, e-benzenediol. 2-bromo-1A-benzenediol1-chloro-4-nitronaphthalene. Ethylene chlorobromide. Diphenoyl chloride.Succinyl chloride 4-chloroquinoline.

Ethanoyl iodide. Hexanoyl chloride.

Decanoyl chloride.

2-bromoethanol.

2-chloroethanol. bis-b-chloroethylether. Chloromethoxy methane.Cyclohexylbrcmide. Carbon tetrachloride. 2-chl0ro-3-hexene.2-bromo-2-pentene. B-brornoA-octene.

The halogen-containing compounds most useful in the practice of thepresent invention are those which contain a halogen from the groupconsisting of bromine, chlorine and iodine and the elements carbonand/or hydrogen. These compounds are the halogen-substitutedhydrocarbons and hydrogen halides. There is no critical limit to themolecular weight of the modifying compound other than one ofpracticality in handling. It will generally be somewhat preferred, froma purely practical standpoint, to use those compounds which are normallyliquid, but those that are normally gaseous are even more preferred. Inthe practice of the present invention, the preferred halogen compoundsare the monoand di-halogen substituted hydrocarbons of no more than 6carbon atoms and the'hydrogen halides. Though all of the halogens fromthe group consisting of bromine, chlorine and iodine are operable in thepresent invention, it is generally preferred to use thosev compoundscontaining chlorine and bromine with bromine being preferred overchlorine.

Among the sulfur-bearing compounds useful in the present invention arethe following non-limiting examples:

allyl sulfide benzyl disulfide Z-methyl-l-butanethiol benzyl sulfide3-methyl-1butanethiol tert-octanethiol Z-methyI-Z-butancthiolbutylsulfide butyl disulfide ethanethiol 1,2-ethanedithiol ethyldisulfide ethylene sulfide ethyl sulfide l-heptanethiol isoamyldisulfide isobutyl sulfide methyl sulfide l-naphthalenethiol phenyldisulfide Z-methyl-l-propanethiol 2,2-thiodiethanol acetyl disulfideo-bromo-benzenesulfonic acid acid o-formyl-benzenesulfonicp-chloro-benzenesulfonic acid acid benzyl sulfoxidemethyl-benzenesulfonic acid butyl sulfate 2,5-dimethylthiophene2,2-bithiophene butyl sulfone dithio-carbamic acid thiono-carbamic aciddithiol-carbonic acid dodecyl sulfate ethionic anhydride ethyl sulfoneethyl sulfuric acid methyl sulfoxide Z-bromothiophene butyl sulfoxidethiol-carbamic acid trithio-carbonic acid cetyl sulfate1,2-cthanedisulfonic acid ethyl sulfite ethyl sulfoxide mcthanethiolb,b'-dichloroethyl sulfide 2-chlorothiophene 2,5-diiodothiophene vinylsulfide methyl sulfate dichlorophenylphosphene 2,3-dimethylthiophencl-decanol sulfate methyl sulfite sulfide V bis-(b-dichloroethyl) sulfideethyl methyl sulfide tetradccyl sulfate thionaphthene Z-mcthylthiophenca-toluenethiol sulfur dissolved in dialkylalkanolaminethionaphthenequinone 3-methylthiophene elemental sulfur bcnzoyldisulfide As noted from the above list of compounds, the sulfurbearingmodifying agents may contain such elements other than sulfur'as carbon,hydrogen, oxygen, nitrogen, chlorine, bromine, iodine, and the like.Among the preferred modifying compounds are sulfur and suchsulfurbearing compounds as mercaptans or thiols both aliphatic andaromatic, hydrogen sulfide, thio ethers and thiourea. Also within thislist of preferred compounds are those derived from dissolving sulfur intertiary amines at elevated temperatures. The preferred modifyingcompounds are sulfur and sulfur-bearing compounds containing theadditional elements of carbon and/or hydrogen. When using thesesulfur-bearing compounds containing carbon and hydrogen, it is generallypreferred that they contain no greater than 20 carbon atoms, with thosecontaining less than 10 carbon atoms being preferred.

It is, of course, not necessary that the modifying agent be limited to acompound which will form one of the above-mentioned hydrogen halides ora sulfur compound which will form hydrogen sulfide. It is within thescope 'of the present invention that a combination of the two types ofcompounds may be used. For example, the present invention contemplatesthe use in combination as a modifying agent such compounds as bromopropane and bcnzyl mercaptan. Also, one compound may contain both ahalogen atom and a sulfur atom and may suffice as a combinationmodifying agent. Such an example is 2- bromothiophene.

The amount of modifying agent necessary in carrying out the process ofthe present invention is such :as to cause a molar concentration in thereaction mixture of no less than 0.01 mole percent. Seldom will the molepercent of the modifying agent in the reaction mixture exceed 50percent. A preferred amount of modifying agent is that amount which willproduce a concentration of modifying agent in admixture with theparaflin hydrocarbon and methyl-substituted cyclic compound within therange of 0.5 to 5.0 mole percent.

Temperatures at which the present invention is most often operated arewithin the range of 450 to 850 C. A preferred range of temperatures foroperating the process of the present invention is 500 to 550 C.Generally, the pressures of the process of the present invention are inexcess of p.s.i.g., preferably within the range of from about 2000 toabout 5000 p.s.i.g.

The method whereby the modifying agent and the reactants are broughtinto contact with one another is critical only to the extent that thereshould be a thorough, intimate contact between these components.Reactants and modifying agent may be concurrently introduced into areaction zone which may be a batch container or a reaction chamberdesigned for continuous flow. If the process of the present invention iscarried out as a continuous process, the reactants and modifying agentmay be intro- 7 duced into contact with one another by concurrent,crosscurrent or countercurrent flow. Further, either the reactants oreither of the reactants or the modifying agent may be passed though astationary liquid column of the other or others to effect the necessarycontact.

What is claimed is:

1. A thermal non-catalytic process for producing ethylsubstitutedcompounds which comprises introducing paraffin hydrocarbons and anunsaturated cyclic compound having at least one methyl-substituent intoa reaction zone concurrently with a modifying agent selected from thegroup consisting of compounds and elements Which at the conditions ofthe reaction zone will produce a compound selected from the groupconsisting of HCl, I-IBr, HI, H 8 and combinations thereof, the reactionzone being maintained at a temperature of at least 450 C. and thepressure of at least 100 p.s.i.g.

2. The process of claim 1 wherein the paraffin hydrocarbons contain 2 to20 carbon atoms per molecule.

3. The process of claim 2 wherein the paraffin hydrocarbons aren-paraffins.

4. The process of claim 3 wherein the n-paraffins have 3 to carbon atomsper molecule.

5. The process of claim 1 wherein the methyl-substituted unsaturatedcompound is a methyl-substituted aromatic hydrocarbon.

6. The process of claim 1 wherein the methyl-substituted unsaturatedcyclic compound is a methyl-substituted hetero-cyclic compound.

7. The process of claim 1 wherein the methyl-substituted unsaturatedcyclic compound is a methyl-substituted cycloolefinic hydrocarbon.

8. The process of claim 1 wherein the methyl-substituted unsaturatedcyclic compound is a methyl-substituted cyclo-diolefinic hydrocarbon.

9. The process of claim 1 wherein the paraffin hy-drocarbons are presentin the reaction zone in mole ratio to the methyl-substituted unsaturatedcyclic compound of 1:100 to 100:1.

10. The process of claim 1 wherein the modifying agent is ahalogen-substituted hydrocarbon of no greater than 6 carbon atoms and inwhich the halogen is one selected from the group consisting of iodine,bromine, chlorine and combinations thereof.

11. The process of claim 1 wherein the modifying agent is selected fromthe group consisting of HCl, HBr, HI and combinations thereof.

12. The process of claim 1 wherein the modifying agent is selected fromthe group consisting of iodine, bromine, chlorine and combinationsthereof.

13. The process of claim 1 wherein the modifying agent is elementalsulfur.

14. The process of claim 1 wherein the modifying agent is a sulfurbearing compound selected from the group consisting of mercaptans,hydrogen sulfide, thioethers, sulfur dissolved in tertiary amines, andthioureas.

15. The process of claim 1 wherein the amount of modifying agent is suchas to cause a molecular concentration in the reaction zone within therange of 0.10 to 50.0 mole percent.

16. The process of claim 1 wherein the temperature is within the rangeof 450 to 850 C.

17. The process of producing ethylbenzene which comprises introducingtoluene and a n-paraffin hydrocarbon of 4 to 8 carbon atoms per moleculein a mole ratio of 1:100 to :1 into a reaction zone concurrently with amodifying agent selected from the group consisting of compounds andelements which at the conditions of the reaction zone will produce acompound selected from the group consisting of HCl, HBr, HI, H 8 andcombinations thereof, the reaction zone being maintained at atemperature of at least 450 C. and the pressure of at least 100 p.s.i.g.

18. The process of producing ethylnaphthalene which comprisesintroducing methylnaphthalene and a n-paraflin hydrocarbon of 4 to 8carbon atoms per molecule in a mole ratio of 1:100 to 100:1 into areaction zone concurrently with a modifying agent selected from thegroup consisting of compounds and elements which at the conditions ofthe reaction zone will produce a compound selected from the groupconsisting of HCl, HBr, HI, H 5 and combinations thereof, the reactionzone being maintained at a temperature of at least 450 C. and thepressure of at least 100 p.s.i.g.

19. The process of producing ethyltol-uene which com.- prisesintroducing Xylene and a n-paraifin hydrocarbon of 4 to 8 carbon atomsper molecule in a mole ratio of 1:100 to 100:1 into a reaction zoneconcurrently with a modifying agent selected from the group consistingof compounds and elements which at the conditions of the reaction zonewill produce a compound selected from the groupconsisting of HCl, HBr,HI, H 5 and combinations thereof, the reaction zone being maintained ata temperature of at least 450 C. and the pressure of at least 100p.s.i.g.

References Cited UNITED STATES PATENTS 2,883,439 4/1959 Wald 260-6683,198,845 8/1965 Franz 260-668 FOREIGN PATENTS 225,364 11/1959Australia.

DELBERT E. GANTZ, Primary Examiner.

C. R. DAVIS, Assistant Examiner.

1. A THERMAL NON-CATALYTIC PROCESS FOR PRODUCING ETHYLSUBSTITUTEDCOMPOUNDS WHICH COMPRISES INTRODUCING PARAFFIN HYDROCARBONS AND ANUNSATURATED CYCLIC COMPOUND HAVING AT LEAST ONE METHYL-SUBSTITUENT INTOA REACTION ZONE CONCURRENTLY WITH A MODIFYING AGENT SELECTED FROM THEGROUP CONSISTING OF COMPOUNDS AND ELEMENTS WHICH AT THE CONDITIONS OFTHE REACTION ZONE WILL PRODUCE A COMPOUND SELECTED FROM THE GROUPCONSISTING OF HCL, HBR, HI, H2S AND COMBINATIONS THEREOF, THE REACTIONZONE BEING MAINTAINED AT A TEMPERATURE OF AT LEAST 450*C. AND THEPRESSURE OF AT LEAST 100 P.S.I.G.